The force-displacement characteristics of the cheek will be studied to: a) Evaluate the forces generated by the displaced cheek by the impingement of certain orthodontic appliances, b) Measure the "rest-displacement" of the cheek associated with the equilibrium position of the natural dentition. A hydraulic system using a slave and master electroformed bellows with LVDT devices to monitor both force and displacement will be activated by an analog controller. Using computer programs for data taking, calibration, and analysis, data on two groups of subjects will be taken: 1. An adult population for the orthodontic appliance impingement study, and 2. An adult population destined to receive immediate full dentures.